Effects of temperature, time, atmosphere and sealing geometry on defects occurred in borosilicate glass-kovar alloy seal

Ardestani, Seyed Sadegh Khayat; Dashtizad, Valiollah; Kaflou, Ali

doi:10.1016/j.ceramint.2020.09.032

Cited by 16 publications

(3 citation statements)

References 18 publications

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“…The spreading of the ends of the liquid glass during the atmospheric wetting process also results in the formation of special structural bodies. Based on the analysis of the cross-sectional morphology of the wetted interior and the edges of the ends and in conjunction with the theory of reoxidation growth of the Kovar [ 14 ], the entire wetting process of the high-borosilicate glass and the Kovar can be explained in three stages, as shown in Figure 20 .…”

Section: Resultsmentioning

confidence: 99%

“…Glass-to-metal sealing is a technique in which glass is melted and laminated to the metal being sealed. Due to the differences in the physicochemical properties of glass and metal and the fact that the glass-to-metal sealing process has been challenging [ 9 ], the most common method used today is to generate an oxide film on the surface of a Kovar alloy, which acts as a buffer layer to connect the glass to the metal [ 10 , 11 , 12 , 13 , 14 ]; however, the quality of the metal-to-glass sealing bond is influenced by several key parameters, such as the thickness, composition and microstructure of the oxide influences. A short preoxidation time to form a thin oxide layer can lead to weak chemical bonding; conversely, a long oxidation time to form a porous and sparse oxide layer can lead to seal failure.…”

Section: Introductionmentioning

confidence: 99%

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Microscopic Analysis of the Wetting Morphology and Interfacial Bonding Mechanism of Preoxidised Kovar Alloys with Borosilicate Glass

2023

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This paper investigates the wettability of Kovar alloys with high-borosilicate glass and microscopically analyses the mechanism of wettability and diffusion between Kovar and borosilicate glass. First, Kovar was oxidised at 800 °C for 5, 15, 25, 35, and 60 min to observe the oxide morphology of the Kovar surface layer and to analyse the composition of the oxide layer. To investigate the wetting pattern formations of Kovar and high-borosilicate glass under different wetting temperatures, times, and preoxidation conditions, Kovar and high-borosilicate glass obtained from different oxidation treatments were held at 1060 °C for 20 min for wetting experiments, and the glass–metal wetting interface morphology and elemental distribution were observed using SEM and EDS. The elemental diffusion at the wetting interface between the borosilicate glass and the Kovar with different preoxidation and at the glass spreading boundary was investigated. The longitudinal diffusion of the liquid glass in the metal oxide layer formed a new tight chemical bond of Fe2SiO4, and the lateral diffusion of the liquid glass in the Kovar surface layer formed a black halo.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microscopic Analysis of the Wetting Morphology and Interfacial Bonding Mechanism of Preoxidised Kovar Alloys with Borosilicate Glass

2023

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“…The method for sealing the lid with the base plays a key role in the reliability of the package. Solder sealing, glass sealing and parallel seam welding are the most commonly used methods for sealing the lid [6]. For solder sealing or glass sealing, the sealing mechanisms are almost the same.…”

Section: Introductionmentioning

confidence: 99%

A new method for preventing stress cracking in repairable ceramic packages by changing the sealing ring shape

Yao,

Tian,

Fang

et al. 2023

Mater. Res. Express

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High-reliable ceramic packages are impressionable to the parallel seam welding (PSW) parameters leading to low yield and reliability. In this study, the structure of the ceramic package was modified by changing the sealing ring to improve weldability and high-temperature reliability. Three types of ceramic packages with different-shaped sealing rings, which are conventional rectangular rings, notch inward rings, and notch outward rings, were fabricated by Au-Sn soldering and a follow-up PSW process. The packages with the rectangular ring failed in the subsequent high-temperature aging test. The packages with the notch inward ring exhibited an early failure after PSW. Cracks were generated in the Au-Sn solder and propagated into the ceramic substrate. The packages with the notch outward ring exhibited remarkable weldability and reliability. Sequential thermo-structural coupling was used to simulate the temperature and stress distribution in the packages. The maximum principal stress in the aforementioned ceramic substrates rapidly increased to approximately 170.0 MPa, 168.5 MPa and 101.4 MPa in the PSW process. Stress concentration existed at the outside corner around the rectangular and notch inward-shaped sealing rings. The maximum temperature at the local position in the ceramic was raised to 250.3 °C, 238.6 °C and 157.2 °C depending on the shape of the sealing ring. The extra transmission path in the notch outward ring relieved thermal mismatch and deformation at the Au-Sn/ceramic interface during PSW. The packages with notch outward rings were recommended especially in the repairable ceramic packaging.

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Mathematical modeling and flow thermodynamics study of borosilicate glass melt after external addition of Cr2O3

Guo,

Liu,

Wang

et al. 2024

Ceramics International

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Effects of temperature, time, atmosphere and sealing geometry on defects occurred in borosilicate glass-kovar alloy seal

Cited by 16 publications

References 18 publications

Microscopic Analysis of the Wetting Morphology and Interfacial Bonding Mechanism of Preoxidised Kovar Alloys with Borosilicate Glass

Microscopic Analysis of the Wetting Morphology and Interfacial Bonding Mechanism of Preoxidised Kovar Alloys with Borosilicate Glass

A new method for preventing stress cracking in repairable ceramic packages by changing the sealing ring shape

Mathematical modeling and flow thermodynamics study of borosilicate glass melt after external addition of Cr2O3

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